SK channel activation potentiates auranofin-induced cell death in glio- and neuroblastoma cells

Area of Science:

• Oncology
• Neuroscience
• Pharmacology

Background:

• Brain tumors, particularly gliomas, exhibit high resistance to conventional therapies.
• Ion channel activity, specifically small-conductance calcium-activated potassium (SK/KCa) channels, significantly influences glioma proliferation and survival.
• The combined therapeutic potential of existing anti-cancer agents and SK channel modulators remains largely unexplored.

Purpose of the Study:

• To investigate the efficacy of a combined treatment using the gold derivative auranofin and the SK channel activator CyPPA against neuroblastoma and glioblastoma cells.
• To evaluate the impact of this combination therapy on mitochondrial function and cell viability.
• To determine if this strategy can overcome therapeutic resistance in brain tumors.

Main Methods:

• Utilized auranofin to target thioredoxin reductases and induce cancer cell death.
• Employed CyPPA to activate SK channels in neuroblastoma and glioblastoma cell lines.
• Assessed mitochondrial integrity, respiration, energy production, and overall toxicity in vitro and in patient-derived glioblastoma neurospheres.

Main Results:

• The combination of auranofin and CyPPA induced significant mitochondrial damage and potentiated auranofin's toxicity in neuroblastoma cells.
• Impairment of mitochondrial integrity, respiration, and energy generation was observed.
• These effects were replicated in patient-derived glioblastoma cells but not in non-cancerous HT22 cells, indicating tumor-specific action.

Conclusions:

• Integrating auranofin with SK channel openers represents a promising strategy to enhance anti-cancer agent effectiveness.
• This approach effectively targets mitochondrial health, offering a potential method to overcome resistance in brain tumors.
• The findings highlight a novel therapeutic avenue for treating aggressive brain cancers like glioblastoma.